Cellular kinetics associated with the development of acquired cellular resistance.

Mice infected with either BCG or Listeria monocytogenes display the same type of cellular response pattern. In both infections there is an intense proliferation of splenic lymphoid cells, a coincident proliferation of differentiated macrophages, and a subsequent production of macrophages with increased metabolic potential. The temporal relations between these events and the onset of host resistance indicate that lymphoid cell proliferation and macrophage proliferation are essential events in the response which leads to cellular resistance against facultative intracellular parasites.